Preparing dental fillings



(No Model.)

A. W. JOHNSTON. PREPARING DENTAL FILLINGS.

No. 503,419. Patented Aug. 15 1893.

WITNESSES E6 7 NlTE arena FFICE.

ALBERT W. JOHNSTON, OF NEW BRIGHTON, NEIV YORK, ASSIGNOR TO THE S. S. IVHITE DENTAL MANUFACTURING COMPANY, OF PHILADELPHIA,

PENNSYLVANIA.

PREPARlNG DENTAL FILLINGS.

SPECIFICATION forming part of Letters Patent No. 503,19, dated August 15, 1893.

Application filed January 16, 1893. Serial No. 58,489. (No model.)

To CLZZ whom zit may concern:

Be it known that I, ALBERT W. JOHNSTON, of New Brightomin the county of Richmond and State of New York, have invented a new and useful Improvement in Dental Gold Filling and in the Method of Preparing It, of which the following is a specification.

My invention relates to an improved gold filling for use by dentists for filling cavities in teeth.

My object is to provide a pure gold filling in the form of blocks of varying sizes suitable for insertion into the cavities to be filled, with the body or main portion of each block com- I 5 posed of gold in a plastic or spongy condition readily spreading under pressure to conform to the irregular walls of the cavities being filled, and having an outer surface of gold foil serving as a binder to hold together and guard against the breaking up or separation of the body during the manipulations to which the gold is subjected, as Well as protect the body against too easy penetration by the plugging instruinentin condensing the filling 2 5 in the cavities.

In accordance with my invention I employ electrolytically deposited gold, obtained in a plastic or spongy mass by well known process and sometimes termed matte gold, and this 0 mass is cut into smooth surfaced sheets or slabs of suitable thickness, which after being thoroughly annealed have gold foil smoothly applied to one or both sides, and are then subjected to heat sufficient to cause adhesion 3 5 or welding of the surfacing foil to the plastic or spongy body sheets or slabs. After this the so-surfaced sheets are cut into strips of desired width, and these strips are finally severed transversely into blocks of suitable shapesandsizes,leavingthespongyand plastic body of matte gold exposed or uncoated with foil at the edges of the blocks on the lines of the cuts made in severing the surfaced sheets or slabs into strips and blocks. I thus, as will hereinafter more fully be explained, preparatory to specific designation of the subject matter claimed, provide a most efiicient filling differing from the foil-surfaced fillings heretofore employed.

In the accompanying drawings:Figure 1 so represents the mass of gold removed from the electrode upon which it has been deposited. Fig. 2 shows one of the body sheets or slabs into which the mass is severed. Fig. 3 represeuts a body sheet as having gold foil applied to one side. Fig. 4- shows a body sheet surfaced on opposite sides with foil. Fig. 5 shows a surfaced sheet with lines indicating the cuttinginto strips. Fig. 6 shows strips with lines indicating how they may be cut into blocks; 50 and Fig. '7 shows blocks of various forms cut from the strips.

A mass A of electrolytically deposited gold having been obtained in Well known way, it is cut into slabs or sheets B of suitable thick- 6 5 ness, with smooth surfaces, and each of these sheets after being annealed is smoothly surfaced with gold-foil 0 upon one side as shown by Fig. 3, or upon both sides, as represented by Fig. 4:. The bodysheets so provided upon -7o one or both sides with foil, are next subjected to heat to cause a close adhesion, integral connection or welding of the foil to the body sheets. Next the surfaced sheets are cut into strips D of suitable widths as will be under- 7 5 stood by reference to Figs. 5 and 6, and these strips are severed transversely, at any desired angle, into blocks or piecesEof sizes suitable for insertion into cavities as used for filling by dentists. It will be seen that the blocks thus produced have their bodies of matte gold exposed or uncoated with foil for portions of their surface.

In preparing the body sheets it is i1nportant to provide smooth surfaces for the application of the foil sheets, and in the severing of the mass into sheets, the surfaced sheets into strips, and the strips into filling pieces or blocks, care must be taken to guard against the crumbling or disintegration, as well as prevent injurious compression of the material, the body portion of which yields very readily to pressure. In severing the material very thin rotary steel knives or disk cutters, revolving at a high rate of speed, and as 9 5 sharp as possible, have been found suitable for the Work.

As is well known, electrolytically deposited gold is verybulkyin proportion to its weight, is soft and highly plastic, and is of a spongy nature readily separating or tearing into pieces under manipulation. The plastic quality of this materialrenders it highly desirable for dentists use,but its'properties of readily tearing or breaking up and of being easily penetrated by packing instruments detract considerably from its value, used by itself, as a filling material. By the employment of the gold foil surface connected integrally with the body of electrolytically deposited gold, as hereinbefore set forth, a binder is provided to hold together the coherent body,and a tough and not easily penetrated surface is provided to resist injury by the packing instruments during condensation of the filling.

I am aware that fillings have heretofore been made of gold in the form of dust or in fine particles applied to gold foil and united thereto by heat. Also that astrip of electrolytically deposited gold has been wrapped in gold foil to form a roll, after which the roll was cut by shearsinto lengths forming pellets for insertion into cavities of teeth; the result of this process being that pellets, the different golds of which were not integrally united, were produced with the severed ends closed together, and necessarily compressed, thus giving to the inclosed bodies of the pellets difierent densities in different portions and imparting an uneven hardness to the filling. Such several fillings differ from mine in which there is an integral union between a coherent mass of electrolytically deposited gold and the surfacing foil; while the homogeneous or uniform structure and even density throughmaterial cutting it "into strips and severing the strips into filling blocks with their bodies exposed or uncoated with foil at the edges, substantially as set forth.

2. A dental gold filling block consisting of the body of electrolytically deposited or matte gold in mass of homogeneous structureand uniform density throughout, surfaced on one or two sides with gold foil integrally connected therewith, and exposed or uncoated with foil for the remainder of its surface, substantially as set forth.

In testimony whereof I have hereunto subscribed my name. 7 V

ALBERT W. JOHNSTON.

WVitnesses: y

O. S. VIDEoN, H. S. BEDELL. 

